Patellofemoral instability (PFI) occurs when patellar maltracking becomes symptomatic, ranging from a positive apprehension test to recurrent dislocation. It is a common condition in the knee, particularly in the adolescent population. There are a range of modalities helpful in investigating this group of patients. Emphasis must be placed on obtaining a good history and clinical examination, but appropriate imaging is essential. In reviewing this topic, many questions remain unanswered, in terms of the treatment options, but evidence is emerging and the trends for treating this complex group of patients are evolving. There has been a clear amalgamation of two schools of thought, with one school using a single universal method to treat all patients with PFI with a medial patellofemoral ligament (MPFL) reconstruction, and the other surgically correcting each identifiable risk factor, tailored to the individual patient. Over time, these two schools of thought have merged, and procedures such as trochleoplasty have been on the rise in combination with an MPFL reconstruction. The results of these procedures have been encouraging, although more robust long-term clinical data are still awaited.